Sewing machine presser bar mechanisms



Jan. 19, 1960 R. E. JQHNSON sswmc MACHINE PRESSER BAR MECHANISMS 2Sheets-Sheet Original Filed Nov. 29, 1954 nvmvron Ralph E. JohnsonFig.l.

ATTORNEY Jan. 19, 1960 R. E. JOHNSON SEWING MACHINE PRESSER BARMECHANISMS Original Filed Nov. 29, 1954 2 Sheets-Sheet 2 INVENTOR. RalphE. Johnson A TTORNE Y Pate t ddan. .19, .1960

SEWING MACHINE PRESSER -BAR Ralph E. Johnson, Mountainside, NJ.,assignor to .The

Singer Manufacturing Company, Elizabeth,N.J., a corporation of NewJersey.Orlginal application November 29, 1954, Serial INo.

471,766, now Patent No. 2,862,468, dated rDecember 2, 1958. Divided andthis application January .17, 1957, Serial No. 634,755

Claims. (Cl. "112-158) This invention relates to improvements .in sewingmachines and has for its principal object-to provide a .sewing machinewith a novel and meritorious presser-bar mechanism for effectivelymaintaining the workmaterial in proper relation with the work-supportingbed of a sewing machine and for assisting in the feeding ,of the workover the bed. 7

A further object of the invention is to providea sewing machine of theornamental stitch type with a presser-bar mechanism which is adapted tocooperate withaneedlebar mechanism in the manner such that theneedle-bar may be shifted laterally of the direction of work feed andabout a portion of the presser-bar mechanism.

A still further object of the invention is toprovide a .zigzag stitchsewing machine with a needle-bar mounting which will establish arelatively large pivotalradius .for ,the needle. I With the above andother objects in view, the 'invention comprises the devices,combinations and arrangements of parts hereinafter described inconnection withthe accompanying drawings which illustrate a preferredembodiment of the invention from which the several .features of theinvention and the advantages attained thereby will ,be readilyunderstood by thoseskilled in the art.

In the drawings: 7

Fig. 1 represents a vertical sectional view taken through the headportion of a sewing machine incorporating the present invention.

Fig. 2 represents, on a reduced scale, a fragmentary side elevationalview in axial cross sectionof the sewing machine illustrated in Fig. 1.

Fig. 3 represents, on an enlarged scale, a sectional view takensubstantially on the line 3-3 of Fig. '2.

Fig. 4 represents, on a large .scale, a fragmentary section view takensubstantially on the line 44 of Fig. 3.

The following detailed description relates to sewing machine presser-bardevices adapted to be employed on asewing machine of the type disclosedin my co-pending application Serial No. 471,766, filed November 29,1954, now Patent No. 2,862,468 of which this application is a division.

As illustrated in the drawings, the frame of the sewing machine in whichthe present invention is incorporated comprises a substantiallyrectangular base 10 forming at its upper side a work-supporting surfaceor bed-plate and provided at its underside with a plurality ofdownwardly extending walls 1111 forming a box-like enclosure, thedownwardly facing opening of which is closed -.by a bottom cover plate12 held in ,place by a thumb nut 13 fitted over a stud 14 extending.downwardlyfrom the underface of the .base 11.

Suitably secured .upon the hollow bed l0vis a-vertically disposed'hollowstandard 15 which carries an overhanging bracket-arm 16 terminating in ahollow...head "17 in which is mounted a reciprocatory needleabar .18'and a presser-bar 19. V

The needle-bar 18 is. provided .witha conventional eyepointed rneedle 20whichis adapted atoacooperate in the "by the numeral 21.

[32 is aplunger 34 of which the lowenportion to engage the spring33,while. its upper, portion .bore 25 -is laterally offset fromithe lower:is provided with a cylindricalmember -37 which is secured ."formationof lock-stitches.wvithsarrotary loop-takerdisposed beneaththe .bedaplate10 and generally designated Mounted upon the lower end of thepresser-bar 19 is .a conventional type .of presser-foot 22 whichcooperates withalthroat-plate 23 and a feed-dog 24in the feeding .of-thework..over. the work-support and away from the operator.:TheTthroat-plate 23'is carried by the work-support .10.

Asis specifically disclosed and described in my above noted co-pendingapplication .Serial- No. 471,766 the machineillustratedin.Fig..1.comprises a zigzag type'of needle-bar -18 which .isadapted-in addition to being reciprocated in the direction of its.length, to be periodically I shifted back and forthlaterally of thedirection of work feed to produce *zigzagstitches in cooperationwith-the rotary loop-taker21.

The v.presser bar mechanism whichforms the subject of the presentinvention is located within the hollow portion of the head :17 andaissupported in a pair of substantially opposed upperand-lowercylindrical bores 25 and -26.formedrespectively.in-theportions 27 and 28of thehead 17. Referring particularly'to Figs. 1 and 2 thereispositioned within-thelower-bore 26 a hollow .plunger sleeve 29 securedwithinthe b'ore by means of a set screw 30. Slidingly mounted .withinthe bore 31 of the sleeve 29 is the=presserbar :19 having at its lowerportion, as is hereinabove noted, raconventional type-of presser foot22, and being provided within its upper portion with ahollow bore 32-Wltl1lI1 WhlCl'l is disposed a coil spring 33. Slidinglyreceived'withinthe presser-bar bore is adapted is formed with acup-shaped member '35 provided in its upper surface vwith an annulargroove 36.

Asmay be particularly: observed from'Fig. 3, the upper bore '26 and itwithin .the bore 25 by'means of a setscrew 38, which together with ashoulder portion 39 maintains the cylindricalmember 37 in afixed;position-at:alltimes relative to the machine frame.

As hereinabove noted, the depending cylindrical member 37 functions as apivot support for the needle-bar gate 40 which is maintained "inposition upon the member 37 by means of a collar 41 and its associatedset screw 42. The depending member 37 is provided in its lower portionwith an internal cylindrical bore 43 in which is Slidingly mounted asecond plunger 44 whose lower rounded end portion 45 is adaptedto bereceived within the groove 36 of the plunger cap 35. The upper portionof the bore 43 communicates directly with a threaded bore which isadapted to'receivethe threaded end 47 of a manually adjustable screw48wwhose lower end is adapted to engage the second plunger 44 for thepurpose of shifting the same lengthwise 'of its axis thereby to compressthe spring 33 through the medium of the'first plunger 34 to the end thatthe spring 33 will :bias the presser bar 19 with its associatedpresser-foot 22 downwardly toward the sewing machine work-support 10.

Referring particularly to Fig.1 .the longitudinal axes of the upperplunger 44 and the presser-bar 19 are disposed in parallelism with eachother and with the needle-bar 1t and that, as hereinabovenoted,th'elongitudinal axis of the needle-bar 18 forms substantially an elevendegree angle'with the vertical to the end that Ithe presser-bar andneedle-bar are inclined relative to the work-supporting surface 10 in amanner such thatthe operatoris afforded an unobstructed view of theneedle 20 and the presser-foot 22. :With the presser-bar 19 offsetforwardly from its upper spring-biasing plunger 44 a construction isprovided which permits the needle-bar 18 to have an optimum turningradius about the axis of the plunger 44 and at the-same 'time permitsthe needle and presser-bars 18 and 19 to be properly spaced to the endthat the presser-foot 22 and" the needle 20 are disposed in a properside-by-side relation. The cooperating upper. and lower presser-bar"plungers 44 and 34 permit this ofiset construction due to the fact thatthey are interconnected by means of a plunger cup 35. Still referring toFig. l, the upper portion of the presserbar 19 has clamped thereto bymeans of a screw 49 an abutment member 50'against which a presser-barlifter cam 51 is adapted to be shifted by a manual movement for thepurpose of lifting the presser-foot 22 off the work support so 'astofacilitate the insertion and removal of a work-piece. The presser-barliftingcam 51 is formed as an integral part of a presser-bar liftinglever 52 which is pivoted to the machine frame in a conventional mannerby a screw 53 threaded directly within the frame.

As it is best shown in my co-pending application Serial No. 471,766, theneedle-bar 18 is shifted laterally of the direction of work feed bymeans of the gate 40 which in turn is pivoted about the member 37 by wayof a pitman 54. The pitman 54 is shifted endwise of itself by mechanismnot herein shown. As illustrated in Figs. 2 and 4, the left-hand end ofthe pitman is provided with a'pair of apertures 55-55 through which passcap screws 5656 which function adjustably to lock that end of the pitmanto a C-shaped block 57 in a manner such that the pitman 54 may beshifted lengthwise of itself and relative to the block 57 for adjustmentpurposes. It is to be understood that the C-shaped block 57 has the freeend portions of its limbs pivotally receiving a pin 58 whoseintermediate portion is locked within the needle-bar gate 40 by way ofset screws 5959. This gate 40 is apertured as at 60 so as to bepivotally mounted upon the depending cylindrical member 37. The gatemember 40 is maintained in a proper upright position upon the member 37by way of the collar 41. From the above, it is to be understood that thegate 40 affords a pivotal connection which will permit the left hand endof the pitman 54 as viewed in Fig. 4, to shift endwise of itself for thepurpose of shifting the needle-bar 18 back and forth laterally of thedirection of work feed in a manner as is best described in my co-pendingapplication Serial No. 471,766.

The pivotal movement of the gate 40 about the member 37 will swing theupper portion of the needle-bar 18 in an are due to the fact that theupper portion of the needlebar is slidingly mounted within a ball 59seated within the hollow portion 60 of the gate 40. The lower portion ofthe needle-bar is slidingly mounted within a ball 61 seated within ahollow portion 62 formed within a stationary portion 28 of the sewingmachine frame. From this it will be understood that the swingingmovements of the gate 40 will effect a swinging movement of the needleto the end that the latter will shift laterally of the normal directionof work feed.

With the presser-bar 19 offset forwardly from its upper spring-biasingplunger 44 a construction is provided which permits the needle-bar 18 tohave an optimum turning radius about the axis of the plunger 44 and atthe same time permits the needle and presser-bars 18 and 19 to beproperly spaced to the end that the Dresser-foot 22 and the needle 20are disposed in a proper side-by-side relation.

Having thus set forth the nature of the invention, what I claim hereinis:

1. In a sewing machine, the combination of a frame including a hollowhead having upper and lower vertically spaced walls providing a pair ofupright laterally spaced parallel cylindrical bores, an elongatedpresser-bar slidably mounted within and lengthwise of the lower borewith its upper end terminating within the hollow portion of the head, aplunger-bar slidably mounted within and lengthwise of the upper borewith its lower end terminating within the hollow portion of the head, anabutment member carried by the end of one of the two bars at a locationwithin the hollow portion of the head and extending laterally of itscarrying bar to be disposed within the path of endwise movement of theother bar, and a spring engaging one of the two bars and biasing theabutment member and the adjacent end of the other bar into separableengagement.

2. In a sewing machine, the combination of a frame including a hollowhead having upper and lower vertically spaced walls providing a pair ofupright laterally spaced parallel cylindrical bores, an elongatedpresser-bar slidably mounted within and lengthwise of the lower borewith its upper end terminating within the hollow portion of the head, aplunger-bar slidably mounted within and lengthwise of the upper borewith its lower end terminating within the hollow portion of the headbelow the upper wall, an abutment member carried by the end of one ofthe two bars at a location within the hollow portion of the head andextending laterally of its carrying bar to be disposed within the pathof endwise movement of the other bar, a spring engaging one of the twobars and biasing the abutment member and the adjacent end of the otherbar into separable engagement, a needle-bar gate pivotally mounted aboutthe longitudinal axis of the plunger-bar, and a needle-bar mountedwithin the gate in normally parallel relation with the longitudinal axisof the plunger-bar and the presser-bar and with the normal lateralspacing between the needle-bar and plunger-bar axes being greater thanthe normal lateral spacing between the needle-bar and resser-bar axes.

3. In a sewing machine, the combination of a frame including a hollowhead having upper and lower vertically spaced walls providing a pair ofupright laterally spaced parallel cylindrical bores, an elongatedpresser-bar slidably mounted within and lengthwise of the lower borewith its upper end terminating within the hollow portion of the head, ahollow cylindrical sleeve having its one end portion fixed within theupper bore with its other end depending into the hollow portion of thehead, a needle-carrying gate carried by and pivotally mounted about thelongitudinal axis of the cylindrical sleeve, a needle carried by thegate, a plunger-bar slidably mounted within and lengthwise of thecylindrical sleeve with its lower end terminating within the hollowportion of the head, an abutment member carried by the end of one of thetwo bars at a location within the hollow portion of the head andextending laterally of its carrying bar to be disposed within the pathof endwise movement of the other bar, and a spring engaging one of thetwo bars and biasing the abutment member and the adjacent end of theother bar into separable engagement.

4. In a sewing machine, the combination of a frame including a hollowhead having upper and lower vertically spaced walls of which the loweris provided with an upright cylindrical bore, an elongated presser-barslidably mounted within and lengthwise of the bore with its upper endterminating within the hollow portion of the head, a hollow cylindricalsleeve fixed to the upper wall with its longitudinal axis laterallyspaced from and in parallelism with the longitudinal axis of thepresser-bar, a needlecarrying gate carried by and pivotally mountedabout the longitudinal axis of the cylindrical sleeve, a needle carriedby the gate, a plunger-bar slidably mounted within and lengthwise of thecylindrical sleeve with its lower end terminating within the hollowportion of the head below the sleeve, an abutment member carried by theend of one of the two bars at a location within the hollow portion ofthe head and extending laterally of its carrying bar to be disposedwithin the path of endwise movement of the other bar, and a coil springengaging one of the two bars to bias the abutment member and theadjacent end of the other bar into separable engage ment.

5. In a sewing machine, the combination of a frame including a hollowhead having upper and lower vertically spaced walls providing a pair ofupright laterally spaced parallel cylindrical bores, a plunger-barslidably mounted within and lengthwise of the lower portion of the upperbore with its lower end terminating within the hollow portion of thehead, a manually operable member mounted within the upper portion of theupper bore thereby adjustably to determine the position of the barlengthwise of the upper bore, an elongated resser-bar slidably mountedwithin and lengthwise of the lower bore with its upper end terminatingwithin the hollow portion of the head, the upper portion of theresser-bar being formed with an upright cylindrical bore, a secondplunger-bar slidably mounted within the upper portion of the resser-barbore with the upper end of the second plunger-bar being disposed withinthe hollow head clear of the resser-bar, tin abutment member carried bythe end of one of the 6 two plunger-bars and extending laterally of itscarrying bar to be disposed within the path of endwise movement of theother plunger-bar, and a coil spring engaging one of the twoplunger-bars to bias the abutment member and the adjustment end of theother plungerbar into separable engagement.

References Cited in the file of this patent UNITED STATES PATENTS572,040 Willcox Nov. 24, 1896 678,926 Allen July 23, 1901 2519,452Galkin e Aug 22, 1950

